/*
 * (c) Copyright 2019 Palantir Technologies Inc. All rights reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.palantir.atlasdb.autobatch;

import com.palantir.logsafe.Preconditions;
import java.util.Map;
import java.util.Set;
import java.util.function.Supplier;

public final class CoalescingRequestSupplier<T> implements CoalescingRequestFunction<Autobatchers.SupplierKey, T> {

    private final Supplier<T> supplier;

    public CoalescingRequestSupplier(Supplier<T> supplier) {
        this.supplier = supplier;
    }

    @Override
    public Map<Autobatchers.SupplierKey, T> apply(Set<Autobatchers.SupplierKey> request) {
        Preconditions.checkArgument(request.size() == 1, "invalid request");
        return Autobatchers.SupplierKey.wrap(supplier.get());
    }
}
